The Government has come under renewed pressure to halt arms sales to Saudi Arabia amid claims British-made weapons have been used in air strikes which have killed thousands of civilians in Yemen's civil war.

The cross-party Commons International Development Committee said there was "overwhelming" evidence that the Saudi-led coalition fighting the Houthi rebels had violated international law using equipment supplied by the UK.

In a letter to International Development Secretary Justine Greening, the committee said the flow of arms to Saudi had picked up dramatically since the start of the conflict, with close to £3 billion-worth of export licences being granted in the last six months.

They include £1 billion worth of licences for bombs, rockets and missiles issued in the three months to the end of September last year compared to just £9 million worth of licences awarded over the same period the previous year.

"We are shocked that the UK Government can continue to claim that there have been no breaches of humanitarian law by the coalition and not only continue sales of arms to Saudi Arabia but significantly increase them since the start of the coalition intervention into Yemen," the committee said.

"We are convinced that there is more than a clear risk that weapons sold to Saudi Arabia might be used in the commission of serious violations of international humanitarian law.

"The evidence that we have heard is overwhelming that the Saudi-led coalition has committed violations of international law, using equipment supplied by the UK."

The committee's intervention comes after a leaked United Nations report found that the Saudi-led coalition fighting the Iranian-backed Houthis had targeted civilians in air strikes in a "widespread and systematic" way.

The UN panel of experts said civilians were also being deliberately starved as a war tactic and called for an inquiry into human rights abuses.

The committee chairman, Stephen Twigg, said: "We need an independent, international fact-finding mission to uncover the truth. Until then we should cease selling arms to Saudi Arabia.

"All parties to this conflict should review their obligations under international law and undertake to put civilians and humanitarian work above other interests."